smokin

My 200tdi 110 csw has started to smoke on start up.It has always had a puff of black smoke hot and cold only now there is a cloud of white/blue smoke(worse when cold but still seen hot)and also seems to run like a bag of **** until warm.I did a full service about 1500 miles ago but then did a scotland trip(1300 miles in a week)and this is now happenung.It also has a clacking sound that sounds like it is coming from front lower part of engine.Can anyone give me guidance as to where to start to look,I not a mechanical numpty but I have limited experiance on 200tdi's
Cheers Steve

check the injection pump timing - white smoke is unburnt fuel, which will be most obvious when the engine is cold. Too far advanced will make it clatter also.

also check crank pulley has not come loose.i have just had it on mine it smoked on start up and overrun.crank pulley and crank timing gear had worn on keyway